<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<link rel="stylesheet" href="./css/index.css" />
<title>记事本</title>
</head>
<body>
<section id="app">
  <!-- 输入框 -->
  <header class="header">
    <h1>小黑记事本</h1>
    <input v-model="todoName"  placeholder="请输入任务" class="new-todo" />
    <button @click="add" class="add">添加任务</button>
  </header>
  <!-- 列表区域 -->
  <section class="main">
    <ul class="todo-list">
      <li class="todo" v-for="(item, index) in list" :key="item.id">
        <div class="view">
          <span class="index">{{ index + 1 }}.</span> <label>{{ item.name }}</label>
          <button @click="del(item.id)" class="destroy"></button>
        </div>
      </li>
    </ul>
  </section>
  <footer class="footer" v-show="list.length > 0">
    <span class="todo-count">合 计:<strong> {{ list.length }} </strong></span>
    <button @click="clear" class="clear-completed">
      清空任务
    </button>
  </footer>
</section>
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
<script>
    const app = new Vue({
      el: '#app',
      data: {
        todoName: '',
        list: [
          { id: 1, name: '打麻将如何赢钱' },
          { id: 2, name: '唐丙鑫教你一天五百' },
          { id: 3, name: '拜师费一杯咖啡' },
        ]
      },
      methods: {
        del (id) {
          this.list = this.list.filter(item => item.id !== id)
        },
        add () {
          if (this.todoName.trim() === '') {
            alert('请输入任务名称')
            return
          }
          this.list.unshift({
            id: +new Date(),
            name: this.todoName
          })
          this.todoName = ''
        },
        clear () {
          this.list = []
        }
      }
    })

</script>
</body>
</html>
